The Physics of Noah’s Ark

Paramount Pictures’ approach to Noah is a big-screen extravaganza with Russell Crowe and Jennifer Connelly. I haven’t seen the film yet, but I’m thinking it’s probably a lot different from Crowe and Connelly’s last two pictures together, Winter’s Tale and A Beautiful Mind. I also expect that in future years it may become an Easter/Passover season staple on TV, akin to Charlton Heston’s The Ten Commandments.

Image (c) Kathiann M. Kowalski

Students at the University of Leicester have taken a different approach to the biblical narrative. They decided to figure out whether the ark could have floated. And the answer, according to the university’s press release is:

Now, I would have put in a comma after the second “two.” And at first glance it wasn’t clear to me that the physicists were calculating the buoyancy of the boat versus the animals. I imagined sheep and goats bobbing by in the water.

Actually, the conclusion is that the ark could have floated with about 35,000 pairs of animals on board. And the physics and math used by the group of graduate students is definitely cool.

The group’s calculations considered the buoyancy of the ark, as well as its weight. “[I]n order for it to float, these two forces need to be equal,” says research lead Oliver Youle in the university’s press release.

The research team did have to make various assumptions for their calculations. For example, they took an average of the ancient Hebrew and Egyptian cubit measures. (A cubit is supposed to measure from the elbow to the middle fingertip.)

The team assumed the ark was made from cypress wood. That’s a generally accepted translation for “gopher wood,” which is not known in modern times.

And then the team had to figure out the mass of the animals on board. Since they couldn’t readily weigh specimens of all the species, they relied on earlier research suggesting that the average “animal” weighs as much as a 23.47-kilogram sheep.

“Our conclusions were that the ark would support the weight of 2.15 million sheep without sinking and that should be enough to support all of the species that were around at the time,” says Youle.